G. G. Steger’s research while affiliated with Medical University of Vienna and other places

Background The PALLAS trial investigated the addition of palbociclib to standard adjuvant endocrine therapy to reduce breast cancer recurrence. This pre-specified analysis was conducted to determine whether adjuvant palbociclib benefited patients diagnosed with lower risk stage IIA disease compared to those with higher stage disease. Methods PALLAS was an international, multicenter, randomized, open-label, phase III trial, representing a public–private partnership between Pfizer, the Austrian Breast Cancer Study Group, and the U.S. ALLIANCE Foundation. Patients diagnosed with stage II–III, hormone-receptor-positive, HER2/neu negative breast cancer within 12 months of diagnosis had completed all definitive therapy aside from endocrine therapy (started within 6 months prior to study entry) were eligible. All patients were required to submit a formalin-fixed paraffin-embedded (FFPE) tumor block. Patients were randomly assigned 1:1 to receive standard adjuvant endocrine therapy (of physicians’ choice) for at least 5 years with or without 2 years of palbociclib, administered orally at a starting dose of 125 mg daily, given for 21 days followed by a 7-day break. Results A total of 5,796 patients with HR + /HER2- early breast cancer (including 1,010 with stage IIA) were enrolled. Median follow-up was 50 months for stage IIA patients and 43.1 months overall. In the stage IIA cohort, 4-year iDFS in the palbociclib arm was 92.9% versus 92.1% for ET alone (HR 0.75, 95%CI 0.48–1.19, p = 0.23). There was no differential benefit by histologic grade, chemotherapy receipt, age, or anatomic/clinical risk. Additionally, no benefit to palbociclib was seen in this cohort in invasive breast cancer-free survival (iBCFS), locoregional relapse-free survival (LRFS), distant relapse-free survival (DRFS), or overall survival (OS). For the stage IIB/III patients, 4-year iDFS was 85.3% for palbociclib + ET versus 83.6% for ET alone (HR 0.91, 95% CI 0.77–1.07, p = 0.24). Conclusions and relevance While there were substantial differences in outcome for stage IIA versus IIB/III patients at 4 years of follow-up, the addition of 2 years of palbociclib did not improve outcomes for patients, regardless of stage. Trial Registration ClinicalTrials.gov number NCT02513394 Registered 30 Jul 2015.

Background Adjuvant abemaciclib combined with endocrine therapy (ET) previously demonstrated clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer at the second interim analysis, however follow-up was limited. Here, we present results of the prespecified primary outcome analysis and an additional follow-up analysis. Patients and methods This global, phase III, open-label trial randomized (1 : 1) 5637 patients to adjuvant ET for ≥5 years ± abemaciclib for 2 years. Cohort 1 enrolled patients with ≥4 positive axillary lymph nodes (ALNs), or 1-3 positive ALNs and either grade 3 disease or tumor ≥5 cm. Cohort 2 enrolled patients with 1-3 positive ALNs and centrally determined high Ki-67 index (≥20%). The primary endpoint was IDFS in the intent-to-treat population (cohorts 1 and 2). Secondary endpoints were IDFS in patients with high Ki-67, DRFS, overall survival, and safety. Results At the primary outcome analysis, with 19 months median follow-up time, abemaciclib + ET resulted in a 29% reduction in the risk of developing an IDFS event [hazard ratio (HR) = 0.71, 95% confidence interval (CI) 0.58-0.87; nominal P = 0.0009]. At the additional follow-up analysis, with 27 months median follow-up and 90% of patients off treatment, IDFS (HR = 0.70, 95% CI 0.59-0.82; nominal P < 0.0001) and DRFS (HR = 0.69, 95% CI 0.57-0.83; nominal P < 0.0001) benefit was maintained. The absolute improvements in 3-year IDFS and DRFS rates were 5.4% and 4.2%, respectively. Whereas Ki-67 index was prognostic, abemaciclib benefit was consistent regardless of Ki-67 index. Safety data were consistent with the known abemaciclib risk profile. Conclusion Abemaciclib + ET significantly improved IDFS in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer, with an acceptable safety profile. Ki-67 index was prognostic, but abemaciclib benefit was observed regardless of Ki-67 index. Overall, the robust treatment benefit of abemaciclib extended beyond the 2-year treatment period.

This abstract was withdrawn by the authors. Citation Format: Minichsdorfer C, Bergen E, Steger GG, Pfeiler G, Frantal S, Greil R, Fohler H, Egle D, Balic M, Fitzal F, Wette V, Exner R, Bartsch RA, Gnant M. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-21-02.

Introduction Despite the large use of nab-paclitaxel as a treatment option in metastatic breast cancer (MBC) across different countries, no definitive data are available in particular clinical situations. Areas covered Efficacy, safety and schedule issues concerning available literature on nab-paclitaxel in advanced breast cancer and in specific subgroups of patients have been discussed and voted during an International Expert Meeting. Ten expert specialists in oncology, with extensive clinical experience on Nab-P and publications in the field of MBC have been identified. Six scientific areas of interest have been covered, generating 13 specific Statements for Nab-P, after literature review. For efficacy issues, a summary of research quality was performed adopting the GRADE algorithm for evidence scoring. The panel members were invited to express their opinion on the statements, in case of disagreement all the controversial opinions and the relative motivations have been made public. Expert opinion Consensus was reached in 30.8% of the Nab-P statements, mainly those regarding safety issues, whereas ones regarding efficacy and schedule still remain controversial areas, requiring further data originated by the literature.

Background: Adjuvant chemotherapy (ACT) for breast cancer improves relapse free (BCRFS) and overall survival. Differences in terms of efficacy and toxicity could partly be explained by the significant interpatient variability in pharmacokinetics which cannot be captured by dosing according to body surface area. Consequently, tailored dosing was prospectively evaluated in the PANTHER trial. Patients and methods: PANTHER is a multicenter, open-label, randomized phase III trial which compared tailored, dose dense epirubicin/cyclophosphamide (EC) and docetaxel (D) (tDD) with standard interval 5-fluorouracil/E/C and D. The primary endpoint was BCRFS and the primary efficacy analysis has been previously published. In this secondary analysis, we aimed to retrospectively explore the concept of dose tailoring. Our two hypotheses were that BCRFS would not vary depending on the cumulative administered epirubicin dose; and that dose tailoring would lead to appropriate dosing and improved outcomes for obese patients, who are known to have worse prognosis and increased toxicity after dose dense ACT. Results: Patients treated with tDD had similar BCRFS regardless of the cumulative epirubicin dose (p = 0.495), while obese patients in this group (BMI ≥30) had improved BCRFS compared to non-obese ones (BMI <30) (HR = 0.51, 95% CI 0.30 - 0.89, p = 0.02). Moreover, tDD was associated with improved BCRFS compared to standard treatment only in obese patients (HR = 0.49, 95% CI 0.26 - 0.90, p = 0.022) but not in non-obese ones (HR = 0.79, 95% CI 0.60 - 1.04, p = 0.089). The differences were not formally statistically significant (p for interaction 0.175). There were no differences in terms of toxicity across the epirubicin dose levels or the BMI groups. Conclusions: Dose tailoring is a feasible strategy which can potentially improve outcomes in obese patients without increasing toxicity and should be pursued in further clinical studies. Clinicaltrials.gov identifier: NCT00798070.